20720258785 has 4 divisors (see below), whose sum is σ = 24864310548. Its totient is φ = 16576207024.

The previous prime is 20720258747. The next prime is 20720258827. The reversal of 20720258785 is 58785202702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15702094864 + 5018163921 = 125308^2 + 70839^2 .

It is a cyclic number.

It is not a de Polignac number, because 20720258785 - 2¹⁵ = 20720226017 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2072025874 + ... + 2072025883.

It is an arithmetic number, because the mean of its divisors is an integer number (6216077637).

Almost surely, 2^20720258785 is an apocalyptic number.

It is an amenable number.

20720258785 is a deficient number, since it is larger than the sum of its proper divisors (4144051763).

20720258785 is an equidigital number, since it uses as much as digits as its factorization.

20720258785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4144051762.

The product of its (nonzero) digits is 627200, while the sum is 46.

The spelling of 20720258785 in words is "twenty billion, seven hundred twenty million, two hundred fifty-eight thousand, seven hundred eighty-five".